• Journal of KIISE:Information Networking
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• v.30 no.3
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• pp.329-342
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• 2003

Most of the existing multicast routing protocols for ad-hoc networks do not take into account the efficiency of the protocol for the cases when there are large number of sources in the multicast group, resulting in either large overhead or poor data delivery ratio when the number of sources is large. In this paper, we propose a multicast routing protocol for ad-hoc networks, which particularly considers the scalability of the protocol in terms of the number of sources in the multicast groups. The proposed protocol designates a set of sources as the core sources. Each core source is a root of each tree that reaches all the destinations of the multicast group. The union of these trees constitutes the data delivery mesh, and each of the non-core sources finds the nearest core source in order to delegate its data delivery. For the efficient operation of the proposed protocol, it is important to have an appropriate number of core sources. Having too many of the core sources incurs excessive control and data packet overhead, whereas having too little of them results in a vulnerable and overloaded data delivery mesh. The data delivery mesh is optimally reconfigured through the periodic control message flooding from the core sources, whereas the connectivity of the mesh is maintained by a persistent local mesh recovery mechanism. The simulation results show that the proposed protocol achieves an efficient multicast communication with high data delivery ratio and low communication overhead compared with the other existing multicast routing protocols when there are multiple sources in the multicast group.

• Analytical Science and Technology
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• v.26 no.4
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• pp.268-275
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• 2013

Many kinds of liquid spray products are used in livelihood activities these days. Spray products can be distinguished by the target to be sprayed (like into the air or on human skin (body)). Because human can be exposed to volatile organic compounds (VOC) emitted from spray products, some considerations on safety or hazard of spray products should be needed. In this study, emission characteristics of VOCs were investigated against 10 types of liquid spray products (6 skin spray and 4 air spray products). The concentrations of benzene and toluene were determined by gas chromatography/mass spectrometry (GC/MS) equipped with a thermal desorber (TD). Their average concentrations from 6 skin spray products exhibited$ 5.64{\pm}1.95$ ($mean{\pm}S.D$) and $8.52{\pm}2.89$ ppb(w), respectively. In contrast, those of 4 air spray samples had $7.30{\pm}1.31$ and $7.19{\pm}1.78$ ppb(w), respectively. If liquid contents in spray samples are completely vaporized in one cubic meter (1 m3) after spraying for 10 seconds, their mean concentrations of skin spray products are $31.7{\pm}8.80$ (benzene) and $50.5{\pm}17.1{\mu}g/Sm^3$ (toluene). In contrast, those of air spray products are $24.0{\pm}4.30$ (benzene) and $23.6{\pm}5.83{\mu}g/Sm^3$ (toluene). The estimated concentration levels of benzene from two types of products (31.7 and $24.0{\mu}/Sm^3$) exceeded the Korean atmospheric environmental guideline ($5{\mu}g/Sm^3$). The results of this study thus suggest that some measures should be made to reduce or suppress the contents of VOC in spray products.

• Applied Chemistry for Engineering
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• v.29 no.3
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• pp.342-349
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• 2018

In this study, the physicochemical properties, emulsifying capacity, moisture content and cytotoxicity of the composite material produced by transesterification reactions of the olive oil (olive oil esters) were investigated for cosmetic applications. Olive oil esters with short (S) and long (L) reaction times were studied. From the TLC-image analysis, composition ratios of the olive oil esters S were found to be 5.2, 24.1, 46.4, and 21.9% for mono-, di-, tri-glyceride, and fatty acid ethyl ester, respectively. Those of the olive oil esters L were 4.1, 24.7, 40.6, and 28.8% for mono-, di-, tri-glyceride, and fatty acid ethyl ester, respectively. The iodine value, acid value, saponification value, unsaponified matter, refractive index, and specific gravity were determined and purity tests were also carried out and normalized to establish standards and testing methods for using olive oil esters in cosmetics. To evaluate their emulsifying capacities, the O/W emulsion was prepared without surfactants and the formation of the emulsified particles were confirmed. After 5 days of applying the olive oil esters to human skin, the skin moisture retention was improved by 13.1% from the initial state. For the evaluation of toxicity on human skin cells, the olive oil esters showed 90% or more of the cell viability at $0.2-200{\mu}g/mL$. These results suggested that olive oil esters can be applied as natural/non-toxic ingredients to cosmetics industries.

• Journal of Food Hygiene and Safety
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• v.33 no.2
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• pp.140-145
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• 2018

The skin of the human body occupies the largest surface area of the body and acts as a protection for the person's internal organs. As such, the skin is a major target of oxidative stressors, and these oxidative stressors are known to contribute to skin aging over the course of time. For the most part, an antioxidant is an effective approach to utilize to prevent symptoms related to the reactive oxygen species (ROS)-induced aging of the skin. Therefore, we investigated the antioxidant and anti-aging activity of the leaves of the Quercusaliena Blume extract (QBE). In our study, we confirmed that the cell viability tested with XTT {2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide innersalt} assay was not affected up to a concentration of $100{\mu}g/mL$. In addition, the cell viability of HDF cells induced by hydrogen peroxide was recovered from 81% to 104% after treatment with QBE, which showed the greater protective effect than that of ascorbic acid. Treatments of QBE dose-dependently inhibited reactive oxygen species (ROS) production in HDF cells induced by hydrogen peroxide, which correlated with their protective effects on cell viability. Since QBE treatment exhibited the suppression effect of skin aging by decreasing the ROS production, QBE could be used as a not only natural anti-aging but also antioxidant resource.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.33 no.4
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• pp.209-217
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• 2007

Melanin plays an important role in protecting human skin from UV radiation and determines the race and skin color. Melanin is also major target for developing skin-whitening cosmeceuticals. Recently, as the market size of skin-whitening cosmeceuticals has rapidly expanded, related researches and developments are also focused on maximizing the safety and efficacy. Also, patents of skin-whitening materials have been increasing steadily for ensuring the competitive power. Patent also shows the research trend of industry and institutes. In this review, we analyze the trend of research and development based on the patent application of skin-whitening cosmeceuticals.

• The Journal of the Convergence on Culture Technology
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• v.10 no.2
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• pp.547-553
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• 2024

If congenital fever left untreated, it can cause atopic dermatitis. It is very important to manage the surface temperature of the neonatal's head during sleep. Baby pillows were mostly developed with cotton materials due to their delicate skin, or they were used for head correction due to their flexible skeletons. This paper measured the surface temperature of baby head in a sleep and analyzed the trends to figure out the PCM effect which to prevent the congenital fever. In addition it was performed a usability evaluation from baby's parents to investigate their satisfaction. According to the results, PCM is effective in regulating skin temperature of neonatal's head to prevent the congenital fever.

• The Korean Journal of Pesticide Science
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• v.15 no.2
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• pp.218-229
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• 2011

Lepimectin is a insecticide agent. In order to register this new pesticide, the series of toxicity data on animal testing were reviwed to evaluate its hazards to consumers and to determine its acceptable daily intake. Lepimectin was mostly excreted by feces. It has low acute oral toxicity while it has no dermal, ocular irritation and skin sensitization (As the result of subchronic, chronic toxicity and carcinogenicity showed changes of hematology and clinical biochemistry parameter of serum and blood.). Two-generation reproduction toxicity, genotoxicity, carcinogenicity and prenatal development toxicity were not proven. Therefore, the ADI for Lepimectin is 0.02 mg/kg/ bw/day, based on the NOAEL of 2.02 mg/kg/ bw/day of two-years carcinogenic toxicity study in rats and applying an uncertainty factor of 100.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.4 s.48
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• pp.525-532
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• 2004

N-acyl taurates are known as environmental-friendly and non-irritating to skin. In this study, the physicochemical properties of N-acyl taurates, which are amide-type anionic surfactants, were measured and also compared with sulfate-type anionic surfactants that show low biodegradability and are highly irritating to skin. The possibility of replacing the currently existing sulfate-type surfactants by N-acyl taurates was examined. Based on the experimental results, shampoos were formulated with these anionic surfactants and their stability and properties were measured. The possibility of application of amide-type surfactants to personal care cleaner was evaluated. Experimental results show that N-acyl taurates have various favorable aspects in making personal care cleanser: high viscosity, low surface tension, and low CMC values. These properties of N-acyl taurates generate nano-scale particles in emulsion, which is stable due to its high viscosity. This emulsion also has good cleaning ability with small amount of usage due to easy penetration into contaminants. Shampoo with N-methyl oleyl taurate showed high yield point and constant viscosity, and formed stable emulsion with nano- scale uniform particles. These results suggest that N-acyl taurates play an important role in making stable Interior structure in shampoo, and which improves the storage property.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.35 no.3
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• pp.219-228
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• 2009

This study was performed to evaluate a deodorant body wash with 1.0 wt% of triclosan and 0.4 wt% of bamboo salt, which have an inhibitory effect on axillary malodor. In this studies, in vitro antibacterial study and the clinical study, which was designed by randomized assignment, double-blind and cross-over, were performed. In the antibacterial study, test sample, which was body wash having 1.0 wt% of triclosan and 0.4 wt% of bamboo salt, have a potent antibacterial effect on Corynebacterium glutamicum, Corynebacterium xerosis, Corynebacterium jeikeium. In the clinical study, test sample has a potent and significant deodorizing effect on axillary malodor and an antibacterial efficacy. And its efficacy was maintained for 9 h at least. There was no side effect during the period of clinical study. Consequently, body wash, containing 1.0 wt% of triclosan and 0.4 wt% of bamboo salt, has the effectiveness and the safety about axillary malodor reduction.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2000.04a
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• pp.14-15
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• 2000

현재의 농업에서 농약의 사용은 불가결한 것이다. DDT의 등장으로 농약만능시대의 막이 열린 이래 세계에서 10만종 이사의 농약이 탄생했다. 현재 전세계의 생산량은 매년 1천만 톤을 넘어섰고 일본의 경우 등록되어 있는 농약수는 원체(화합물종류)로서 367종, 상품명으로서는 약 5800 종류가 판매되고 있다. 년간 일본의 농약생산량은 약 60만 톤으로 농약의 수출량과 수입량이 거의 같기 때문에 생산량이 사용량에 상당하는 것으로 본다. 농약의 식품오염의 측면에서 보면, 단위 면적당 세계 제 1위의 농약 사용국인 일본은 시장에 유통되고 있는 농작물에도 상당한 양의 농약이 잔류하는 것으로 본다. 물론 식품위생법에 26종의 농약에 대해 53작물을 대상으로 하는 잔류농약기준이 있지만, 농약성분이 400종 이상이며 산포 대상이 되는 작물은 53작물보다 훨씬 많다. 또한 한 두 종류의 작물밖에 대상이 되지 않는 농약도 많아서 잔류농약기준은 식품의 안전성 확보면에서는 부족한 것이 많아. 따라서 농산물 생산자 스스로가 농약사용기준을 정확하게 지켜주기를 바랄 뿐이다. 한편으로는, 이러한 현실에 비추어서 농약사용이 일상화된 농업자에게 있어 농약으로 인한 건강상의 문제 또한 적지 않다. 농업자의 건강관리 대책의 일환으로 실시하는 건강진단 및 조사에 따르면, 만성적인 질환뿐만 아니라 농약산포작업후에 나타나는 증세(기침, 피부이상, 불쾌감, 두통, 인후염, 구토)를 경험한 작업자는 예방의학적인 견지에서 농업자의 농약폭로실태파악 및 교육을 해오고 있으나 그다지 설득력을 얻지 못하여 보다 확실한 인체내 흡수량을 측정하는 방법을 생각하게 되었다. 즉 뇨중 농약 대사물을 폭로지표로 하는 생물학적 모니터링(biological monitoring)을 시도, 농업현장에 있어서의 그 실증과 유용성에 대한 검토를 하고자 하였다. 농작업 가운데서 가장 위험하다고 보는 농약산포작업 (수동식 분무기를 이용한 하우스작물 및 동력분무기를 사용한 노지작물)을 대상으로 생물학적모니터링을 실시한 결과 업자의 뇨로부터 농약의 체내흡수를 반영하는 농략의 뇨 분비성 대사물을 측정할 수 있었다. 즉 뇨나 혈액등의 생체시료를 이용한 생물학적모니터링의 농약에의 응용은 서구와는 달리 대부분이 규제가 없는 소규모 자가영농으로 정해진 농약사용지침보다 많은 농약을 사용한다거나, 또는 개인의 습관이나 작업환경에 따라 폭로조건이 달라서 실질적인 폭로-흡수의 정도가 불분명한 경우등에도 충분히 대응할 수 있어 농약사용자 개개인의 농약 폭로-흡수의 정도를 분명하게 밝힐 수 있다. 게다가 평가의 결과를 농약사용의 일선에 있는 농업자에게 피드백 하여 주므로서 농약에 대한 인식을 새롭게 하고 농약취급시의 건강장해예방행동을 촉구하는 등의 효과도 높은 것으로 예방의학적인 유용성이 크다고 볼 수 있다.